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运用ADAMS动力学分析软件对电脑针织横机三角组件和织针组件建模,进行动力学模拟仿真,获得织针组件在三角组件中运行的受力曲线、位移曲线、速度曲线和加速度曲线。对这些曲线进行细致的分析,得出动力学分析结果,为三角组件的改进或优化设计提供理论依据。 相似文献
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根据碳纤维复合材料电气特性,结合地铁列车的运营工况,分析碳纤维地铁车体保护和EMC接地特点.针对碳纤维复合材料车体的接地需求,提出并设计车体接地网方案和拓扑结构,通过仿真分析,给出接地网在车-轨道-地耦合状态下的杂散电流分布规律以及直流侧短路工况下的暂态响应特性. 相似文献
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为探究核主泵设计工况下流场对叶轮结构的影响,对国内某核主泵内部流场进行三维数值模拟,将流场的计算结果作为结构场的初始条件。采用单向流固耦合的方法对核主泵叶轮进行仿真计算,获得在该核主泵设计工况下,叶轮的等效应力分布和总体变形以及模态分布等结构力学特性。结果表明,在该核主泵设计工况下等效应力和总变形都符合核电站运行规定,一阶模态远低于设计工况下核主泵的转频。 相似文献
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针对承压印染设备在使用中缺陷较多、设备寿命普遍较短的问题,运用无损检测、理化分析配合有限元数值模拟的方法,对一批较有代表性的立式染色机进行了全面检验,并将检验过程中发现的典型缺陷进行了总结和分析。根据对快开门结构运行过程中的力学分析结果,从设备应力分布特性角度提出应力腐蚀失效易发部位,并综合设备的检验结果进行比较,进而提出结构优化的建议。缺陷机理分析结果表明,在应力集中、疲劳载荷、腐蚀等因素的综合作用下,承压印染设备极易产生裂纹等使用缺陷,应根据设备的使用情况和腐蚀现状调整检验周期,并针对缺陷易发部位进行定期全面检验。 相似文献
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介绍了一种新型旋转式多点踩压式压曲制块机的结构组成及其工作过程,并运用Solidworks2007COS-MOSWORKS组件对其压力组件关键元件进行有限元分析,分析其是否满足要求。利用amesim7.0软件对定位系统中的液压马达的特性进行仿真分析,为更好的设计定位系统打下坚实基础。 相似文献
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目的通过实验室内部能力验证工作的开展对实验室进行质量控制(内部能力验证),来验证实验室的检测能力、检测人员的操作技术水平和仪器设备的运行状态。方法检测方法用GB/T 4789.2-2010《食品微生物学检验菌落总数测定》对合成乳粉进行定量检测分析。结果依据GB/T15483.1-1999《利用实验室问比对的能力验证。第1部分:能力验证计划的建立和运用》,用Z比分数对被考核实验室的检测结果作出评价和分析。此次内部能力验证共有20个实验室参加,分析检测数据20个,检测数据的满意率为75%。结论通过对各个实验室开展内部能力验证,有助于发现实验室检测分析中存在的问题及检测结果的不合格项,从而找出检测结果离群的各种原因,依照能力验证纠正措施,有效地进行纠偏。 相似文献
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ABSTRACT: During moderate electric field (MEF) processing, a voltage applied across a food material may affect the permeability of cell membranes. It is known that high electric fields can cause either reversible or irreversible rupture of cell membranes. In this research, the effect of MEF processing on permeability was studied. Effects of frequency and electric field strength were investigated. Cellular structure was investigated by transmission electron microscopy (TEM). Fermented black tea leaves and fresh or dry mint leaves were placed in tea bags or cut in 1 cm2 squares, depending on the experiment, and immersed in an aqueous fluid medium. Control samples were heated on a hot plate. MEF treatments were conducted by applying a voltage across electrodes immersed in opposite sides of the beaker. Control and MEF‐treated fresh mint leaf samples heated to 50°C were analyzed by TEM. MEF processing significantly increased the extraction yield for fresh mint leaves because of additional electric field effects during heating. Dried mint leaves and fermented black tea leaves were not affected by the treatment type. Low frequency resulted in higher extraction rates for fresh mint leaves. The electric field strength study showed that electrical breakdown is achieved even at low electric field strengths. MEF treatment shows potential to be used as an alternative to conventional heating for extraction from cellular materials. 相似文献
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为了解决虚拟环境下的装配操作问题,采用基于几何约束的方法,建立了基于层次约束结构的虚拟装配模型,对CAD系统的信息采用产品层、部件层、零件层、特征层、几何面层和面片层来表达,从而为虚拟环境下交互式装配和拆卸操作奠定了基础。提出了基于几何面约束求解的精确定位思想,给出了实现步骤,并探讨了该方法针对复合约束的应用情况。给出了几何约束动态识别的有效机制,通过碰撞检测、零件匹配、几何面匹配、优先关系选择等步骤提高约束识别的效率和准确性。实现了虚拟环境下零件的快速准确定位。 相似文献
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为实现掺假羊肉的快速、客观检测,利用电子鼻定性和定量分析混入鸡肉的掺假羊肉糜。单因素试验表明顶空体积、载气流速、样品量和顶空生成时间对电子鼻传感器的响应影响极显著;主成分分析确定了电子鼻检测的较佳条件:样品量10 g、载气流速200 mL/min、顶空容积250 mL及顶空生成时间30 min。在此条件下检测混入鸡肉的掺假羊肉,结果发现采用主成分分析时,掺入鸡肉的比例随主成分一降低而增大,但相邻比例彼此重叠,难以有效区分;采用典则判别分析时,混入不同比例鸡肉的羊肉糜样品能较好地区分;采用主成分回归分析和偏最小二乘回归分析建立的定量预测模型(R2>0.95)能有效预测混入的鸡肉比例。电子鼻在混入鸡肉的掺假羊肉鉴别中具有可行性,论文可为羊肉掺假鉴别提供理论依据。 相似文献
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Frequency Distribution in Domestic Microwave Ovens and Its Influence on Heating Pattern 总被引:1,自引:0,他引:1
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In this study, snapshots of operating frequency profiles of domestic microwave ovens were collected to reveal the extent of microwave frequency variations under different operation conditions. A computer simulation model was developed based on the finite difference time domain method to analyze the influence of the shifting frequency on heating patterns of foods in a microwave oven. The results showed that the operating frequencies of empty and loaded domestic microwave ovens varied widely even among ovens of the same model purchased on the same date. Each microwave oven had its unique characteristic operating frequencies, which were also affected by the location and shape of the load. The simulated heating patterns of a gellan gel model food when heated on a rotary plate agreed well with the experimental results, which supported the reliability of the developed simulation model. Simulation indicated that the heating patterns of a stationary model food load changed with the varying operating frequency. However, the heating pattern of a rotary model food load was not sensitive to microwave frequencies due to the severe edge heating overshadowing the effects of the frequency variations. 相似文献
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本文以一压榨部机架(复式压榨,overpress-1)为例,在原有结构基础上采取不同改进措施,根据动态分析(固频和响应),探讨提高机架许用车速的效果。这一工作对机架设计和对原有机架进行局部结构改进,具有一定的理论意义和实用参考价值。 相似文献
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为了解决织机高车速时综框振动加剧,经纱断头率增加,影响织造效率的问题,对铝合金、碳铝复合和碳纤维复合材料综框的动态设计进行具体分析。根据最新国家标准,通过在Pro/E中建立综框系列模型,然后利用有限元分析软件ANSYS Workbench 14.5进行模态分析,获取了相应的固有频率和模态振型。分析、比较3种材料和结构型式综框的动态特性,为综框的固有频率避开工作频率提供了参考,为综框结构的动态设计提供了理论依据;指出:碳铝复合材料的应用是增强铝合金综框刚度的有效方法;碳纤维复合材料综框比铝合金综框具有更好的动态特性;随着织机幅宽的增大,同种材料的综框固有频率在减小,为了适应织机高速应改进综框结构,如增加横梁高度、增加中间支撑、在铝合金综框上填充碳纤维复合材料。 相似文献
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CLÁUDIO PATRÍCIO RIBEIRO JR MARIA HELENA CAÑO ANDRADE 《Journal of food process engineering》2003,26(2):181-205
The steady‐state operation of the concentrating system from an industrial milk powder plant was studied using a simulation approach. This system is composed of two tubular preheaters, a plate pasteurizer, a thermocompressor and four climbing‐falling‐film plate evaporators operating in a multiple‐effect arrangement. Its simulation was performed using the ASPEN Plus shell, into which calculation routines previously developed by the authors had to be introduced in order to enable the calculation of the plate units. For the thermocompressor, a simulation code based on the solution of a design equation and the overall mass and energy balances was formulated and then introduced into ASPEN. In the validation step, simulation results were compared with operating data of the industrial plant, and a good agreement was verified. A sensitivity analysis of the concentrating system was then performed, considering two different operating variables, namely the milk inlet temperature and the motive steam pressure in the thermocompressor. 相似文献
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电子雕刻系统是转移印花制版的关键设备,在分析电子雕刻系统的执行元件高频电—机械转换器结构的基础上,通过数学模型进行了动态性能仿真和磁场分析,讨论了主要结构参数对性能的影响;采用反射光测量方法研究了其静态滞回特性和幅频响应特性,并在电子雕刻系统上进行了实际应用测试。结果表明,该摆动式电—机械转换器最大输出角位移约为±0.0064 rad(刻针针尖位移±65μm),滞环小于5.5%,幅频宽可达3100 Hz,是一种结构简单、动作可靠、频响高、线性好的高频电—机械转换器,能够满足电子雕刻系统对电—机械转换器性能的需求。 相似文献